One of the most important and most neglected steps in creating a thriving planted aquarium is the substrate. Depending on your level of experience, you might have even tried growing in clown puke. Fortunately, there are much better choices out there, so let’s jump right in. I’ll show you a bunch of great substrates, and help you decide which is the best for your tank.
Top Planted Aquarium Substrates
1. Carib Sea Eco Complete – Best Planted Tank Substrate for Newbies
I love this stuff. Early in my fishkeeping career, I never strayed from the “party line” of using SeaChem’s Flourite brand, but Carib Sea offers the best value I’ve found in planted substrates. The only issue with their line is that I’m not a fan of their sands.
Eco Complete has a great nutrient profile, looks good in the tank, and produces less silt in the water than most on the market. It’s also available at a great price most of the time, which just adds to the allure, especially for a beginner.
Most plants thrive in this one, taking root easily in the porous rocks and going from there. It may not be the richest source of nutrients out there, but it has a decent lifespan before you need to switch to root tabs.
Now, let’s touch on a couple of bad things. The first is that Carib Sea is not compatible with Bee Shrimp, Discus, or other critters that require an acidic pH. It’s not terrible, but it’ll raise your pH some. It’s also a bit sharp and large for nano-tanks.
That said, Carib Sea Eco Complete is an excellent introductory substrate. It supports all plants just fine. You just don’t want to use it with overly sensitive animals.
2. Seachem Flourite Dark – Runner Up
Flourite was, at one point, the go-to substrate for planted tanks. If you had asked me ten years ago what I recommended, I would have asked if you wanted sand or gravel and told you to go with the appropriate Flourite.
It’s still great, but it generally costs more than my current favorite. It has a generous amount of iron and doesn’t affect the pH of the water column. That means it’s suitable for all animals, and it would be my go-to for a Discus or Bee Shrimp tank.
Despite the chunkier nature of Flourite, it’s actually great for rooting plants. Stem plants are sometimes bothersome to plant without a top layer, but they’ll quickly root in the porous substrate. It also makes a good spot for bacteria to gather.
The main issue, and my main reason for switching, is that it clouds. You’ll need to rinse it extensively, however. My preferred method is to use a bucket and just fill it, dump it, and refill until the water is clear. Cheesecloth also works. Avoid using a strainer; it takes a ridiculously long time.
For a neutral, but nutrient-filled substrate with a long track record, Flourite Dark is excellent. Just be aware you’re paying for the legacy and rinse, rinse, rinse.
3. Seachem Onyx Sand – Best Planted Aquarium Sand
If you’re going for sand, then you’re in for a treat. This is my personal favorite sand-like substrate, and it’s nutrient-rich as well. The consistency here is a bit different than the larger Flourite substrates, and the material is harder as well.
While harder, this is an excellent option for tanks with a lot of bottom-dwellers due to the small granules. It has a shiny, black look to it as well, although it still falls a bit on the “dark grey” side rather than true black.
Like all Flourite products, it has a great nutrient profile with plenty of iron. It’s not exceptional in that regard, although some people have a lot of luck as it promotes healthy roots.
There are two minor issues. The first is the same as all Flourite substrates: you need to rinse it thoroughly, or it will cloud the tank. The second is that it often continues to produce clouds of dust after it’s been settled.
Overall, if you’re looking for a ready-to-go sandy substrate, then you’ll want to take a close look at Seachem’s Onyx Sand. It’s hard to beat unless you’re willing to do a custom solution.
4. ADA Aqua Soil Amazonia – Best for Carpet Plants
Carpet plants were kind of Takashi Amano’s thing, and the substrate released by the late aquarist’s company is perfect. It has a fine consistency, but more than that, it has ideal nutrients for carpeted plants.
It has excellent nutrients, buffers your pH levels, and creates an overall fantastic environment for your plants. It also lowers water hardness, making it a favorite for those who keep sensitive fish like German Blue Rams.
The granules here are between 1/16-⅛”, which puts this somewhere between sand and gravel. They call it soil, although it’s certainly not similar to regular potting soil. The good news is that it’s perfect for that Glosso or HC carpet you’ve been dreaming of.
On the downside? It’s expensive, and it can be dangerous in the hands of the uneducated aquarist. Actually dangerous, you’ll experience an immediate spike in ammonia levels when using this substrate. The tank has to be cycled before adding fish when using this product.
For carpeted plants and heavy growth, however, there’s no substitute for ADA Aqua Soil. Just be careful on the approach, or you may end up with a lot of regrets.
5. U. P. Aqua Shrimp Sand – Best Substrate for Shrimp
If you’re working with any sort of Bee Shrimp(Crystal Red, Blue Bolt, etc.), then you should be aware of the extra parameters involved in their care. You need soft, acidic water, or you’ll end up finding out how fragile they are.
A good substrate can help, and this one is specially made for shrimp. The “trace elements for shrimp” claim is kind of obnoxious. In reality, it’s just a few compounds that lower the pH and KH of the water.
It does work as intended. It’s also lightweight, and the granules are small enough shrimp have no trouble foraging in them. Neither do African Dwarf Frogs or Cory catfish for that matter, so consider it if you like bottom-dwellers.
The main issue I take with Shrimp Sand is that it’s really lightweight. Even a Betta will make it fly, and anytime you move plants or do maintenance, the current will move the substrate. It’s not a great option for advanced aquascaping.
Still, if you’re looking for an excellent substrate for your Bee Shrimp, then you’re in luck. This is a great option for those touchy little critters, but you’ll still have some work to do on your own.
What Makes a Good Substrate for Aquatic Plants?
For those running planted tanks, especially for the first time, it often seems that there are innumerable things to keep track of.
And there are.
But your choice of substrate doesn’t have to be overly complicated. Ask yourself the following:
- What kind of plants do I want?
- What’s the ideal pH for my fish?
- Am I going to focus heavily on carpet plants like Glossostigma elatinoides?
- What color do I want for the substrate?
Those questions will get you going in the right direction. Different plants and situations require different substrates, but there are a few factors that can help guide your decision.
Size and Texture
Planted tank substrates range from rough gravel to finer sands. You won’t find the super-fine sand, which you often see in AGA competitions here. In many cases, the sand used for advanced aquascaping is actually inert.
Play sand makes a good filler, for instance, but doesn’t contain any real nutrients.
As a general rule, chunkier soils cloud the water less when disturbed and work well with stem and crown plants. Crypt sp., Echinodorous sp., and Rotala sp. are good examples of plants that will be right at home in gravel-consistency substrate.
It also makes it easier to replant the cut stems and runners while you’re in the early stages of propagation. Sand often requires digging, and some can cloud the tank for quite some time before settling.
Finer substrates work best for carpet plants. The sand’s weight creates a snug fit, and the plants will stay in place as they grow over the area they’ve been placed.
Rhizome plants, if you’re planning on putting them directly on the substrate, also do well in sand. Their roots can dig into it easily, while in gravel, it takes more time, and just bumping the plant can undo weeks of work.
There are also some small “ball” type substrates that are made to keep shrimp fry safe, but your best defense in that arena is always heavy planting.
Unlike terrestrial plants, where nitrogen is a desired quality in soil, aquatic plants largely acquire their nitrogen through the water column.
Instead, the substrate supplies micronutrients that are in short supply in water. Both nitrogen and phosphorous have a tendency to build up in tanks, hence the need for water changes. Potassium is the main nutrient that is in short supply in aquaria.
There is also another nutrient that’s needed for some plants. Ground cover plants require high levels of iron to continually grow. If you’re planning on using something like Glosso or HC in your tank, it should be a major factor in your choice.
That said, most of us supplement iron with fertilizers. Even the best substrate won’t be able to supply everything.
The pH of your tank is vital for both the plants and animals contained within.
Most planted tank substrates will change it to some degree. The majority will raise it a little bit, but some of the specially engineered soils out there can lower it.
These rarely reach dangerous levels, but some creatures are especially touchy. Rams, Discus, Bee Shrimp, and others are a bit more work than your average family of guppies.
Make sure that the substrate’s pH value is working for you rather than against you. It’s not going to make an enormous difference, but it’s one factor that’s easy to keep in your favor.
Don’t be fooled by substrates which claim that they’re good for the lifespan of a tank. Most substrates are only good for a year, two at most, before they’re out of nutrients.
While tanks that don’t have special requirements can be supported with root tabs, that’s not always the case.
Many substrates also offer buffers that increase the acidity and lower hardness. As these buffers fade, you’ll have to make sure that you can maintain the qualities needed.
Plan on replacing them once they begin to fade, especially if you’re relying on them to change water parameters in your favor.
Planted Tank Substrate FAQ
How Deep Should I Plant My Substrate?
It largely depends on the size of your tank, but the bare minimum should be 1″. Any less than that, most plants will have a lot of trouble rooting in the soil. Most plants will do a bit better with 1 ½” to 2″ of soil. For particularly large specimens, such as Vallisneria gigantica or the various large Echinodorus species, it’s advisable to get at least 3″ immediately under the plant.
How Much Substrate Do I Need?
As a general rule, I advise purchasing at least 1lb/gallon. Due to varying densities, you may end up with a bit more or less when it comes to the overall volume of gravel or sand. Generally, that’s enough to place at least 1″ over the entire bottom of a standard aquarium. For more advanced aquascaping, you may need 1 ¼ to 1 ½ lb/gallon.
Can I Put Live Plants in Regular Gravel?
Sure. You can boil them on the stove too, which will kill them faster and affect your tank’s nitrate levels less. On a more serious note: some plants will do fine in inert gravel or even clown puke, generally things like Hornwort on Anacharis. These plants are actually floating plants, however. Anything which needs to root is going to die in standard gravel quickly.
Can I Use Potting Soil in a Planted Aquarium?
Absolutely, but you need to be rather careful about the whole affair. The first thing which you need to do is make sure that it’s covered with a layer of inert substrate. The most common top layers are play sand and Black Diamond blasting sand. The latter has a bad reputation, but it comes from uneducated opinions. Once placed, do not disturb the soil as it can cause an ammonia spike. It’s perfectly safe, but not a great option for those who regularly rearrange their tanks.
Do You Have to Use a Planted Tank Substrate in an Aquarium With Plants?
For the most part? Yes. There is a caveat: as described in the previous question, you can layer substrates and create your own low-tech solution. It’s a good idea, but frankly… I don’t like doing it. I’ve had some problems that discourage me from recommending it to new aquarists, and the cloudy mess created from moving plants isn’t worth the trouble.
How Can I Keep My Tank From Clouding When I Fill It With a New Substrate?
Virtually all substrates are going to have dust. Even those that are “pre-rinsed” are going to create 6-8 hours of cloudiness if you pour them straight out of the bag. Some can take days to settle properly. I recommend you rinse the gravel yourself before adding it to the tank.
Why Are Some Substrates Labeled Specifically for Shrimp?
There’s a bit of confusion for many people about these. They often claim that they have specific nutrients for invertebrates. That’s sort of true. The shrimp species meant in this case is Bee Shrimp, which are notoriously touchy about their water quality and parameters. This mostly means pH and KH buffers.
Is Nutrient-rich Gravel or Sand a Better Substrate for My Tank?
Gravel is easier to work with in a larger tank, while sand works best for smaller containers. Many people only use sand as a top-layer as well. It’s really a matter of practicality more than anything. Sand is easier to place plants in. Gravel can be a royal pain. Sand can also create anaerobic pockets which are dangerous for water chemistry, but the introduction of Malaysian Trumpet Snails will keep it aerated.
How Much Does the Substrate Affect the Ph of an Aquarium?
Quite a bit. Carib Sea Eco Complete often raises pH 0.2-0.5, depending on the amount. Meanwhile, U. P. Aqua Shrimp Sand can lower it about the same. You’ll almost always need water conditioners anyways. The buffering effect is what you’re looking for in a substrate mostly, and any decent substrate will help negate large swings in pH.
What’s the Best Substrate for a Betta?
Betta are remarkably hardy, but they should be kept with plants. I actually use Eco Complete in my own nano-tank, but it’s a bit chunky for 5 gallons. You should use whatever is best for your livestock and plants… in that order.
Great Substrate, Thriving Plants!
In the end, the best substrate for a planted aquarium has to meet the needs of you and your pets. While there’s a world of them out there, picking one is simple enough. So, why not figure out what you’re planning on doing and pick up the right substrate for your planted aquarium?